Centering New Wheels and Boosting Your Antique's Voltage: Auto Clinic

Q: My son just bought a used car with aftermarket rims. I'm concerned that the centering ring on the hubs is smaller than the corresponding bore on the wheels. This means the wheels may not center correctly, right? Is this safe?WILLIAM STABLER Summerville, SC

A: They should be fine. As to whether the rims fit correctly, that's another Auto Clinic letter in itself. Centering is only one issue. The overall width and offset are also important because they affect handling and steering. The overall diameter of the tire needs to be at least close to the original to avoid changes in gearing that may affect performance. And gross changes in diameter and overall rotating mass may affect ABS performance. Just making sure the replacement wheels physically fit inside the wheel wells without clearance issues to the fenders, suspension and brakes is only a start. You'll need to consult someone who has specific data about your rims and your car.

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Most modern cars use a centering ring that sticks out 10mm to 12mm from the hub, specifically to make sure the wheel is centered within a few thousandths of an inch when it's installed. Not all cars have this ring, however. When you put the wheels on the car, be sure that there is no foreign matter, such as rust or dirt, on the hub or wheel mating surface. This might mean wirebrushing the surface or at least carefully cleaning it with a rag. I prefer to smear a thin coating of antiseize over the surface to prevent any corrosion from sneaking in--but then, I was raised in the Midwest where they pour salt over the road almost every day. Hang the wheel by the studs and fingertighten the top lug nut, then a bottom stud, followed by the rest. Spin the wheel a couple of times to let it settle, then fingertighten all the lugs again. Spin the rim to check that it's centered--the chamfer on the lug nuts will tend to pull the rim toward its center. Unless, of course, you run the first lug nut home with an air wrench instead of tightening all of them gradually.

I'll say again what I've always maintained--never tighten lug nuts with an air wrench, even if you use torque sticks. Torque sticks are short extensions to go between the wrench and the socket, and they're supposed to limit the torque applied to the lug nut. I find them inaccurate and inconsistent. Instead, use this procedure: As above, fingertighten all the lug nuts, then wiggle the rim around and fingertighten again. Next, use a torque wrench to tighten in a crisscross pattern to half the final torque, and then again to full torque. This will keep the wheel centered, prevent warping of the brake discs, and allow you to remove the wheel again on some rainy night to change a flat with the lug wrench in the trunk instead of an air wrench or a 4-ft. cheater.

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Twist and Shout

Q: You published a letter in the January 2006 issue from an individual who needed to remove an improperly installed rearview mirror tab from his windshield. After spending a week with exactly the same difficulty, I asked the local repair shop. They said they had a gadget to remove the tab and would be happy to do it for five bucks. The special gadget turned out to be a crescent wrench. Just put the wrench on the tab parallel with the glass, and twist. The tab will pop right off. FRED COLLINS

Enfield, CT

A:This seemed so simple I had to go out to the shop and try it on a car. Slick. This procedure didn't even leave any adhesive residue on the glass. Many thanks for the tip.

High Voltage

Q: Owners of old tractors and antique cars sometimes put 8-volt batteries in their 6-volt systems to give their starters a little extra juice to spin the old motors faster for easier starting. Is there any harm in this? What does it do to generator polarization or amp/volt readings? RON MINER Conklin, NY

A: Racers use 14-volt batteries to provide a hotter spark and improved cranking, too. The downside is slightly reduced life of some voltage-sensitive components, like light bulbs and electric motors. Regardless of whether the system is positive or negative ground, it will have no effect on ammeter readings--although a stock 6- or 12-volt generator obviously won't give an 8- or 14-volt battery much of a charge. Many antique voltage regulators can be adjusted mechanically. Racers can buy 14-volt alternators, but many race cars have no charging system, so they simply rely on 14-volt off-car battery chargers to recharge the battery between races. The ammeter will still read properly, and the voltmeter will simply reflect the actual voltage of the system.

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Why go 8 volts when you can go 12? If it were my car or tractor, I'd convert it to 12 volts. A good motor shop can rewind the stock starter and generator or alternator appropriately. You will need to replace the bulbs and things like the wiper motors. Use a voltage reducer to run the instruments and the radio.

BORDER="0" CELLSPACING="2" CELLPADDING="0" BGCOLOR="#CCCC99"> SERVICE TIPSHighlights From Tech Service Bulletins

Don't try to use your generic scan tool or even the Honda HDS scan tool in generic mode to try to clear diagnostic trouble codes from the Intelligent Motor Assist system on your 2005 Honda Accord Hybrid. Technical Service Bulletin (TSB) 05-038 says that an earlier version of the on-board software may damage the IMA battery if you don't update to the latest software version first.

Some parts should never be used again. Kia TSB 3-013 prohibits reusing locknuts on the steering, suspension and engine subframe. The nylon inserts in these locknuts are intended to be secure for only a single use, and may not hold properly when reused.

YOU NEED THIS :::::::::::::::::::::::::::::

OTC Stinger Easy Roller

We just got a set of these to use around the PM shop and studio, and they're the most amazing shop tools we've acquired in years. Just position them around the tires, and pump the hydraulic pedal a dozen times or so. Your vehicle, up to 6000 pounds, is lifted clear of the pavement. Now a single person can move the vehicle around the shop floor in any direction. It's great for parking cars out of the way or swinging a car around in its own length. We use them constantly while we're photographing cars for the magazine. The list price for the OTC Stinger is almost $155 each--but if you shop around you can pick up a set of four for under $500. otctools.com

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Eat Carrots and Squint

Q: I have a 1995 Dodge Intrepid. The headlights are really, really bad, especially when it's raining at night. How can I fix this? MARIE CHALSTROM

Via E-Mail

A:PM had an Intrepid in for a long-term test around 1995--and I recall writing in my report that the car's headlights were substandard, particularly on rainy nights. So it's not your imagination. If you have pitted or frosted headlamp lenses, you may be able to polish the surface to resuscitate them for a season or two (see popularmechanics.com/lenses). If the internal reflectors are corroded, the lens assemblies will have to be replaced. Just the parts to do that will come to over $275. If those parts are okay, and you're simply unhappy with the light output of the headlamps like I was, you can try substituting a higher-output bulb. There are several manufacturers who make brighter replacements for your standard 9007 lamp. These stock halogen bulbs are rated at 55 watts low beam/65 watts high beam. Try an aftermarket bulb that claims improved brightness, rather than one that simply changes the color of the lamp to be trendy. If that doesn't cut it on a long, rainy drive, try upgrading to a higher-wattage lamp. Caveat: More powerful high-wattage bulbs generate more heat and may warp the composite plastic housing. They also draw more current and can overheat the wiring. Stick with 85-watt max bulbs.

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